This invention relates to an electromagnetic induction apparatus cooled with a liquid refrigerant sprinkled thereon, and more particularly to a cooling structure for sprinkling a liquid refrigerant on an electromagnetic induction apparatus, for example, a transformer from an upper portion thereof to cool it.
In a conventional transformer having the cooling structure of the type referred to a vertically disposed winding assembly has included a plurality of pancake coils, alternating electrically insulating bases each having spacers stuck to that surface contacted by a mating one of the pancake coils to form cooling ducts therebetween, and an iron core fitted into the winding assembly. A liquid refrigerant has been sprinkled on the winding assembly and the iron core from the upper ends thereof and flowed through the cooling ducts to cool a rectangular electrically conductive wire forming each of the pancake coils and the iron core after which the liquid refrigerant is cooled by an external cooler. The liquid refrigerant thus cooled is again sprinkled on the winding assembly and the iron core to repeat the process as described above. Under these circumstances, the sprinkled liquid refrigerant flows through the cooling ducts formed of the spacers stuck to the electrically insulating bases alternating with the pancake coils. This has resulted in the disadvantage that the liquid refrigerant can not uniformly cool the electrically conductive wire forming each of the pancake coils.
Accordingly, it is an object of the present invention to provide an electromagnetic induction apparatus having a new and improved cooling structure for uniformly cooling an electrically conductive wire forming each of coils involved.